This application seeks to investigate potential behavioral economic markers of prescription opioid addiction in patients with chronic, non-cancer pain. Drawing from previous studies of behavioral economic mechanisms of drug use, Aim 1 will validate a novel laboratory procedure to examine pain-related prescription opioid demand in chronic pain patients who misuse prescribed opioid medications (n =30). A novel opioid purchase task will assess prescription opioid demand under conditions of experimentally-induced pain, and will be validated against an established laboratory task of opioid reinforcement. Aim 2 will utilize a randomized, within-subjects design to compare behavioral economic markers in two groups of patients with chronic pain: 1) those with current prescription opioid addiction (n = 40), and 2) a control group of patients with low opioid misuse risk and no history of opioid or other drug addiction (n = 40). Patients with prescription opioid addiction are expected to exhibit greater delay discounting and prescription opioid demand compared to controls. This research will validate novel experimental methodology and provide initial data on behavioral economic mechanisms of prescription opioid addiction in chronic pain patients. The candidate is a clinical psychologist with an early track record of research productivity in mechanisms of substance use and behavioral interventions in adults with co-occurring disorders. This K23 will provide him with necessary methodological and substantive training to support his long-term research goal of identifying neurobehavioral mechanisms of risk for prescription opioid addiction in patients with chronic pain. The candidate's short-term objectives are to acquire methodological skills in behavioral economics, develop mastery in opioid pharmacology, increase his expertise in the neurobiology of addiction, and gain knowledge in the neurocognitive mechanisms of chronic pain and experimental pain methodology. The candidate will be mentored by senior investigators with expertise in each of these domains. He is supported by the institutional resources of the Center for Behavioral and Addiction Medicine at UCLA, an environment well-suited for the purpose of research in chronic pain and addictions via the integration of addiction medicine into primary care settings. The proposed research and training will equip the candidate with unique expertise in the overlapping and mechanistic neurobehavioral processes implicated in chronic pain, addictive behavior, and reward processing, with the long-term goal of establishing an independent laboratory conducting NIH-funded research in this area.